Draw a number line fairly long about to 15. 2 4/5 would be between 2 and 3. and 9/10 would be close in front of the 1 NOT between the 1 and 2 but before 1 like the very first tick mark in front of the 1.
I really hope this helps in some way. I do not have access right now to add an image up here but I hope the description makes sense.